When we’re young, our friends are our whole world. But when we get older, unfortunately, they often get put on the back burner. Yet we still need friendship in adulthood as much as we do when we’re children. Amid the bustle and mind-numbing routine of everyday life, we deeply value the time we spend talking to them, discussing both trivial and serious issues. And when we meet face-to-face, more often than not we can’t get enough of them, never running out of things to say.

But why do friends seem to disappear as we get older? Is it our fault? And what can we do to avoid losing them completely? This article from journalist Julie Beck tries to answer these vitally important questions.

Friendship means freedom. This is what makes it beautiful...but weak

In the hierarchy of relationships, friendships are at the bottom. Romantic partners, parents, children — all these come first.

This is true in life, and in science, where relationship research tends to focus on couples and families. When Emily Langan, an associate professor of communication at Wheaton College goes to conferences for the International Association of Relationship Researchers, she says, "friendship is the smallest cluster there. Sometimes it’s a panel, if that."

Friendships are unique relationships because unlike family relationships, we choose to enter into them. And unlike other voluntary bonds, like marriages and romantic relationships, they lack a formal structure. You wouldn’t go months without speaking to or seeing your significant other (hopefully), but you might go that long without contacting a friend.

Still, survey upon survey upon survey shows how important people’s friends are to their happiness. And though friendships tend to change as people age, there is some consistency in what people want from them.

“I’ve listened to someone as young as 14 and someone as old as 100 talk about their close friends, and [there are] three expectations of a close friend that I hear people describing and valuing across the entire life course,“ says William Rawlins, the Stocker Professor of Interpersonal Communication at Ohio University. ”Somebody to talk to, someone to depend on, and someone to enjoy. These expectations remain the same, but the circumstances under which they’re accomplished change."

The voluntary nature of friendship makes it subject to life’s whims in a way more formal relationships aren’t. In adulthood, as people grow up and go away, friendships are the relationships most likely to take a hit. You’re stuck with your family, and you’ll prioritize your spouse. But where once you could run over to Jonny’s house at a moment’s notice and see if he could come out to play, now you have to ask Jonny if he has a couple hours to get a drink in two weeks.

The beautiful, special thing about friendship, that friends are friends because they want to be, that they choose each other, is “a double agent,“ Langan says, ”because I can choose to get in, and I can choose to get out."

Throughout life, from grade school to the retirement home, friendship continues to confer health benefits, both mental and physical. But as life accelerates, people’s priorities and responsibilities shift, and friendships are affected, for better, or often, sadly, for worse.

How friendship changes with age

The saga of adult friendship starts off well enough. “I think young adulthood is the golden age for forming friendships,“ Rawlins says. ”Especially for people who have the privilege and the blessing of being able to go to college."

During young adulthood, friendships become more complex and meaningful. In childhood, friends are mostly other kids who are fun to play with; in adolescence, there’s a lot more self-disclosure and support between friends, but adolescents are still discovering their identity, and learning what it means to be intimate. Their friendships help them do that.

But, “in adolescence, people have a really tractable self,“ Rawlins says. ”They’ll change." How many band t-shirts from Hot Topic end up sadly crumpled at the bottom of dresser drawers because the owners’ friends said the band was lame? The world may never know. By young adulthood, people are usually a little more secure in themselves, more likely to seek out friends who share their values on the important things, and let the little things be.

To go along with their newly sophisticated approach to friendship, young adults also have time to devote to their friends. According to the Encyclopedia of Human Relationships, young adults often spend between 10 and 25 hours a week with friends, and the 2014 American Time Use Survey found that people between 20 and 24 years old spent the most time per day socializing on average of any age group.

As people enter middle age, they tend to have more demands on their time, many of them more pressing than friendship. After all, it’s easier to put off catching up with a friend than it is to skip your kid’s play or an important business trip. The ideal of people’s expectations for friendship is always in tension with the reality of their lives, Rawlins says.

“The real bittersweet aspect is young adulthood begins with all this time for friendship, and friendship just having this exuberant, profound importance for figuring out who you are and what’s next,“ Rawlins says. ”And you find at the end of young adulthood, now you don’t have time for the very people who helped you make all these decisions."

The time is poured, largely, into jobs and families. Not everyone gets married or has kids, of course, but even those who stay single are likely to see their friendships affected by others’ couplings. “The largest drop-off in friends in the life course occurs when people get married,“ Rawlins says. ”And that’s kind of ironic, because at the [wedding], people invite both of their sets of friends, so it’s kind of this last wonderful and dramatic gathering of both people’s friends, but then it drops off."

But if you plot busyness across the life course, it makes a parabola. The tasks that take up our time taper down in old age. Once people retire and their kids have grown up, there seems to be more time for the shared living kind of friendship again. People tend to reconnect with old friends they’ve lost touch with. And it seems more urgent to spend time with them—according to socio-emotional selectivity theory, toward the end of life, people begin prioritizing experiences that will make them happiest in the moment, including spending time with close friends and family.

How people find new friends

As they move through life, people make and keep friends in different ways:

Some are independent, they make friends wherever they go, and may have more friendly acquaintances than deep friendships.

Others are discerning, meaning they have a few best friends they stay close with over the years, but the deep investment means that the loss of one of those friends would be devastating.

The most flexible are the acquisitive — people who stay in touch with old friends, but continue to make new ones as they move through the world.

What helps maintain friendships?

And some people do manage to stay friends for life, or at least for a sizeable chunk of life. But what predicts who will last through the maelstrom of middle age and be there for the silver age of friendship?

Whether people hold onto their old friends or grow apart seems to come down to dedication and communication. In Ledbetter’s longitudinal study of best friends, the number of months that friends reported being close in 1983 predicted whether they were still close in 2002, suggesting that the more you’ve invested in a friendship already, the more likely you are to keep it going. Other research has found that people need to feel like they are getting as much out of the friendship as they are putting in, and that that equity can predict a friendship’s continued success.

Hanging out with a set of lifelong best friends can be annoying, because the years of inside jokes and references often make their communication unintelligible to outsiders. But this sort of shared language is part of what makes friendships last. In the longitudinal study, the researchers were also able to predict friends’ future closeness by how well they performed on a word-guessing game in 1983. (The game was similar to Taboo, in that one partner gave clues about a word without actually saying it, while the other guessed.)

"Such communication skill and mutual understanding may help friends successfully transition through life changes that threaten friendship stability," the study reads. Friends don’t necessarily need to communicate often, or intricately, just similarly.

Online communication is not enough

Of course, there are more ways than ever that people can communicate with friends, and media multiplexity theory suggests that the more platforms on which friends communicate — texting and emailing, sending each other funny Snapchats and links on Facebook, and seeing each other in person — the stronger their friendship is. "If we only have the Facebook tie, that’s probably a friendship that’s in greater jeopardy of not surviving into the future," Ledbetter says.

Though you would think we would all know better by now than to draw a hard line between online relationships and “real“ relationships, Langan says her students still use ”real" to mean “in-person.”

There are four main levels of maintaining a relationship, and digital communication works better for some than for others. The first is just keeping a relationship alive at all, just to keep it in existence. Saying "Happy Birthday" on Facebook, faving a friend’s tweet — these are the life support machines of friendship. They keep it breathing, but mechanically.

Next is to keep a relationship at a stable level of closeness. “I think you can do that online too,“ Langan says. ”Because the platforms are broad enough in terms of being able to write a message, being able to send some support comments if necessary." It’s sometimes possible to repair a relationship online, too, (another maintenance level) depending on how badly it was broken — getting back in touch with someone, or sending a heartfelt apology email.

“But then when you get to the next level, which is: Can I make it a satisfying relationship? That’s I think where the line starts to break down,“ Langan says. ”Because what happens often is people think of satisfying relationships as being more than an online presence."

The main enemies of friendship: politeness, and circumstances

“This is one thing I really want to tell you,“ Rawlins says. ”Friendships are always susceptible to circumstances. If you think of all the things we have to do — we have to work, we have to take care of our kids, or our parents — friends choose to do things for each other, so we can put them off. They fall through the cracks."

After young adulthood, he says, the reasons that friends stop being friends are usually circumstantial — due to things outside the relationship itself. One of the findings from Langan’s “friendship rules“ study was that ”adults feel the need to be more polite in their friendships," she says. “We don’t feel like, in adulthood, we can demand very much of our friends. It’s unfair, they’ve got other stuff going on. So we stop expecting as much, which to me is kind of a sad thing, that we walk away from that.” For the sake of being polite.

But the things that make friendship fragile also make it flexible. Rawlins’ interviewees tended to think of their friendships as continuous, even if they went through long periods where they were out of touch. This is a fairly sunny view — you wouldn’t assume you were still on good terms with your parents if you hadn’t heard from them in months. But the default assumption with friends is that you’re still friends.

“That is how friendships continue, because people are living up to each other’s expectations. And if we have relaxed expectations for each other, or we’ve even suspended expectations, there’s a sense in which we realize that,“ Rawlins says. ”A summer when you’re 10, three months is one-thirtieth of your life. When you’re 30, what is it? It feels like the blink of an eye."

Perhaps friends are more willing to forgive long lapses in communication because they’re feeling life’s velocity acutely too. It’s sad, sure, that we stop relying on our friends as much when we grow up, but it allows for a different kind of relationship, based on a mutual understanding of each other’s human limitations. It’s not ideal, but it’s real, as Rawlins might say. Friendship is a relationship with no strings attached except the ones you choose to tie, one that’s just about being there, as best as you can.